For the matter of elevator, one of the multi-use facilities for unspecified public, the JIS has re-established and reformed to apply to the environment in South Korea for the past 20 years. In the aspect of safety assurance, it was inevitable to suggest improved measures. The government, Ministry of Public Administration and Security has secured the safety by enhancing the safety management functions in the elevator inspection standards and expanding its safety device measures. Further, the international inspection standard has been introduced, which is about unifying inspection standard system into the international standard code. In March 14th 2012, the international standard (EN) has been amended and fully announced. Escalator and passenger conveyor among lift devices have several common danger factor that cause safety accident. First, the accident caused by decreased braking power of brake. Second, the accident caused by the rate difference between handrail and tread-board. Third, the accident caused by defects of contraflow preventing device or carelessness inspection. Fourth, the accident caused by wet tread-board or wet floor of platform which makes passenger slip and fall. As the improvements to prevent and reduce these negligent accidents, the inspection list to check and methods should be subdivided and applied for each accident likelihood cause for safety management enhancement and safety assurance of existing escalator and passenger conveyors. The escalators and passenger conveyors without safety devices in existence should be obliged to modify the part of the system or install additional safety device. With making these measures obligations, it requires to improve the system to be suitable for the international inspection standard and to have measures to prevent safety accidents. It also needs to arrange improvements for skid accident of tread-board by the external environment factors such as snow and rain.
본 연구는 바다새 서식지 복원 및 식생복원을 위해 2011년 4월부터 12월까지 전라남도 신안군 칠발도와 소 구굴도지역에 대한 식물군락 및 환경구배에 따른 바닷새 번식지 토양환경 요인을 분석하였다. 토양요인을 분석한 결과 칠발도는 닭의장풀군락이 수분함량, 유기물함량, 염 분농도, 총질소가 높게 나타났으며, 쇠무릎 군락은 낮게 나타났다. 또한, 바닷새 서식처로 이용되는 밀사초 군락은 토양환경요인 분포범위가 넓고 유입종인 쇠무릎군락과 쑥군락은 좁게 나타났다. 소구굴도 밀사초군락 토양pH는 3.14로 가장 낮았고, 갯기름나물군락은 3.84 가장 높게 나 타났다. 수분함량과 유기물함량은 갯기름나물군락에서 가 장 높게 나타났으며, 쇠무릎군락이 35.9%로 가장 낮게 분 석되었다. 염분농도와 총질소는 밀사초군락이 가장 높게 나타났다. 고도에 따른 토양환경특성에서는 칠발도의 경 우 고도가 높아질수록 수분함량, 유기물함량, 염분농도 및 총질소가 낮아지는 유의성을 보였다. 소구굴도 토양수분 함량은 평균 35.73%, 유기물함량 16.38%, pH 3.34로 전 체적으로 산성토양이었다. 토양산성화는 조류분비물에 의 해 영향을 받았을 것으로 판단된다. 염분농도는 평균 2.11 ppt, 총질소는 평균 6.43 mg g-1로 분석되었다. 소구굴도 는 섬면적이 좁고, 고도가 낮아 전체적으로 토양환경요인 의 분석결과는 크게 차이가 나타나지 않았으나, 수분함량 은 환경구배에 대해 고도에 의한 유의성을 보였다.
장미 수경재배시 적절한 엽면적확보와 상품생산에 미치는 절곡 지 굵기의 영향을 확인하기 위해 2011년 4월부터 11월까지 처 리별 절곡지 생장특성과 절화수량 및 품질을 조사하였다. 상품생 산을 위해 굵은 가지를 절곡할수록 절곡지 생체중과 절곡각도가 커진 반면 잎의 량은 6~8mm 굵기의 가지를 절곡하였을 때 엽 면적지수가 3.5로 가장 높았고, 9~11mm인 가지를 절곡하였을 때는 오히려 2.7로 가장 낮았다. 단위면적당 상품수량은 엽면적 지수와 같은 경향을 보였고, 상품률과 절화중, 절화직경은 절곡지 굵기에 비례하였다. 절화 길이와 꽃의 볼륨감이 조화와 균형을 이루어 상품성이 좋았던 등급은 절화 길이가 60~80cm였고, 80cm 이상 지나치게 굵은 가지는 줄기와 잎에 비해 꽃의 볼륨 감이 떨어져 오히려 상품성이 떨어졌다. 이와 같은 이상적인 절 화 생산비율이 6~8mm인 가지를 절곡하였을 때는 63.4%로 9~11mm인 가지를 절곡하였을 때보다 8%가 높았고, 한편으로 상품성이 떨어지는 굵은 절화 비율은 9~11mm인 가지를 절곡하 였을때 28.8%로 6~8mm인 가지를 절곡하였을 때보다 10% 높았다. 지나치게 굵은 가지를 절곡하였을 때는 절곡지 엽면적 감소와 지나치게 굵은 가지의 발생으로 인해 절화수량이 감소하 였다. 절곡후 잎과 상품수량 확보를 위해서는 줄기 굵기가 6~8mm 두께의 가지를 절곡하는 것이 좋을 것으로 판단된다.
낙농에서 젖소의 복지는 일차적으로 젖소가 건강하고 영양상태가 좋으며 질병과 부상이 없는 사 육환경을 의미한다. 최근에는 불량한 사육환경에 의해 야기되는 고통으로부터의 자유라는 개념까지 포괄하여 젖소의 복지를 추구하고 있다. 그러나 지난 10여 년간 낙농산업이 처한 경영상의 어려움 으로 인해 과밀사육이 나타나고 전염성 및 대사성 발병이 증가하고 있다. 또한 지구 온난화에 의한 고온 스트레스로 인해 낙농산업의 생산성이 저하되고 있으며 이러한 지구온난화는 앞으로도 수십 년간 지속될 것으로 전망되고 있어 사육관리에 대한 새로운 전략이 필요한 실정이다. 본 총설에서 는 젖소의 복지측면에서 대두되는 국내외의 문제점을 제시하고 여러 연구결과를 종합적으로 논하고 자 한다.
현재 분리막 여과 공정은 정수처리에서 많은 관심을 받고 있다. 하지만, 분리막의 효율적인 운영을 위하여 '혼화/응집(/침전)' 등의 전처리 시설 설치로 인한 부지면적 및 비용증가와 5~10%의 배출수 문제가 추가적으로 발생한다. 그래서 본 연구에서는 전처리 공정 없이 지표수(한강)에 대하여 가압식 PVDF 분리막[(주)에코니티]으로 운전하여 성능을 검토하였으며 그 결과 1년 동안 화학적 세정 없이 여과 flux가 1~2.4 m/d (at 25℃)로 운전되었고, 유입원수의 탁도와 상관없이 분리막 처리수의 탁도는 0.05 NTU 이하로 안정되게 유지되었다. 또한, 회수율 제고를 위하여 1개월 동안 가압식 배출수(역세수 + 배수)를 침지식 PE 분리막[(주)에코니티]으로 연계하여 2단 막여과 운영을 한 결과 전체 공정 회수율을 99.5%까지 증가시킬 수 있었다.
Axial flow fan under certain condition may stall. The rise in pressure across the impeller blade of an axial flow fan depends on the angle of attack. At a low back pressure, the air volume will be large and the angle of attack is small. In this study, the time dependent Navier-Stokes equations are numerically solved in large size axial-flow fan with groove
이 연구는 대학에서의 교수역량강화를 위한 전략으로 부각되고 있는 “수업컨설팅”의 효과를 측정하기 위한 객관적 평가지표를 개발하기 위한 연구이다. 이를 위하여 기존 문헌 연구를 통해 교수역량에 관련한 국내 연구들을 바탕으로 교수역량 요인들을 추출해 델파이 설문지를 만들어 전국대학 교수학습개발센터에서 수업컨설팅을 업무를 맡고 있는 실무자 20명의 응답으로 2회에 걸친 델파이 조사를 실시하였다. 1, 2차 델파이 조사를 통해 선정된 25개 문항을 놓고 3차 조사는 전문가들의 심층토의를 거쳐 최종 교수역량 평가지표 24개 문항을 선정하였고 각 문항이 속할 대영역의 명칭과 문항 분류를 결정하였다. 수업설계와 준비에 해당하는 부분은 대부분이 문항에서 제외되었고, 실제 수업활동에 속하는 문항이 다수가 포함되었다. 이를 통해 개발된 평가지표가 실천적 교육역량에 속하는 것임을 고려한다면, 수업컨설팅 현장에서 효과적으로 활용될 수 있을 것으로 보인다.
Manganese dioxide (MnO2) is one of the most important cathode materials used in both aqueous and non-aqueous batteries. The MnO2 polymorph that is used for lithium primary batteries is synthesized either by electrolytic (EMD-MnO2) or chemical methods (CMD-MnO2). Commonly, electrolytic manganese dioxide (EMD) is used as a cathode mixture material for dry-cell batteries, such as a alkaline batteries, zinc-carbon batteries, rechargeable alkaline batteries, etc. The characteristics of lithium/manganese-dioxide primary cells fabricated with EMD-MnO2 powders as cathode were compared as a function of the parameters of a manufacturing process. The flexible primary cells were prepared with EMD-MnO2, active carbon, and poly vinylidene fluoride (PVDF) binder (10 wt.%) coated on an Al foil substrate. A cathode sheet with micro-porous showed a higher discharge capacity than a cathode sheet compacted by a press process. As the amount of EMD-MnO2 increased, the electrical conductivity decreased and the electrical capacity increased. The cell subjected to heat-treatment at 200˚C for 1 hr showed a high discharge capacity. The flexible primary cell made using the optimum conditions showed a capacity and an average voltage of 220 mAh/g and 2.8 V, respectively, at 437.5μA.
(Na, K) NbO3 thick film was successfully achieved using a sol-gel coating process with the addition of polyvinylpyrrolidone (PVP) to a metal alkoxide solution. The transparent coating solution, mixed with Nb:PVP = 1:1 in a molar ration, was synthesized by evaporating the solvent to over 62.5 wt%. Additive PVP increased the viscosity of the solution so that the coating thickness could be enhanced. The thickness of the (Na, K) NbO3 film assisted by PVP was ca. 320 nm at the time of deposition; this value is four times thicker than that of the sample fabricated without PVP. Also, due to PVP binding with the OH groups of the metal alkoxide, the condensation reaction in the film was suppressed. The crystalline size of the (Na, K) NbO3 films assisted by PVP was ca. 15 nm smaller than that of the film fabricated without PVP. After the sintering process at 700˚C, the (Na, K) NbO3 films were mainly composed of randomly oriented (Na, K) NbO3 phase of perovskite crystal structure, including a somewhat secondary phase of K2Nb4O11. However, by adding PVP, the content of the secondary phase became quite smaller than that of the sample without PVP. It was thought that the addition of PVP might have the effect of restraining the loss of potassium and that PVP could hold metalloxane by strong hydrogen bonding before complete decomposition. Therefore, the film thickness of the (Na, K) NbO3 films could be considerably advanced and made more crack-free by the addition of PVP.
We have examined the co-doping effects of 1/2mol% NiO and 1/4mol% Cr2O3 (Ni:Cr=1:1) on the reaction,microstructure, and electrical properties, such as the bulk defects and the grain boundary properties, of ZnO-Bi2O3-Sb2O3 (ZBS;Sb/Bi=0.5, 1.0, and 2.0) varistors. The sintering and electrical properties of Ni,Cr-doped ZBS, ZBS(NiCr) varistors werecontrolled using the Sb/Bi ratio. Pyrochlore (Zn2Bi3Sb3O14), α-spinel (Zn7Sb2O12), and δ-Bi2O3 were detected for all ofcompositions. For the sample with Sb/Bi=1.0, the Pyrochlore was decomposed and promoted densification at lowertemperature by Ni rather than by Cr. A homogeneous microstructure was obtained for all of the samples affected by α-spinel.The varistor characteristics were not dramatically improved (non-linear coefficient, α=5~24), and seemed to formZni..(0.17eV) and Vo.(0.33eV) as dominant defects. From impedance and modulus spectroscopy, the grain boundaries werefound to have been divided into two types, i.e., one is tentatively assigned to ZnO/Bi2O3 (Ni,Cr)/ZnO (0.98eV) and the otheris assigned to a ZnO/ZnO (~1.5eV) homojunction.
In this study we aimed to examine the co-doping effects of 1/6mol% Co3O4 and 1/4mol% Cr2O3 (Co:Cr=1:1)on the reaction, microstructure, and electrical properties, such as the bulk defects and the grain boundary properties, of ZnO-Bi2O3-Sb2O3 (ZBS; Sb/Bi=0.5, 1.0, and 2.0) varistors. The sintering and electrical properties of Co,Cr-doped ZBS, ZBS(CoCr)varistors were controlled using the Sb/Bi ratio. Pyrochlore (Zn2Bi3Sb3O14), α-spinel (Zn7Sb2O12), and δ-Bi2O3 were formed inall systems. Pyrochlore was decomposed and promoted densification at lower temperature on heating in Sb/Bi=1.0 by Cr ratherthan Co. A more homogeneous microstructure was obtained in all systems affected by α-spinel. In ZBS(CoCr), the varistorcharacteristics were improved (non-linear coefficient, α=20~63), and seemed to form Zni..(0.20eV) and Vo.(0.33eV) asdominant defects. From impedance and modulus spectroscopy, the grain boundaries were found to be composed of anelectrically single barrier (0.94~1.1eV) that is, however, somewhat sensitive to ambient oxygen with temperature. The phasedevelopment, densification, and microstructure were controlled by Cr rather than by Co but the electrical and grain boundaryproperties were controlled by Co rather than by Cr.
We aimed to examine the co-doping effects of 1/6mol% Mn3O4 and 1/4mol% Cr2O3 (Mn:Cr=1:1) on the reaction,microstructure, and electrical properties, such as the bulk defects and grain boundary properties, of ZnO-Bi2O3-Sb2O3 (ZBS;Sb/Bi=0.5, 1.0, and 2.0) varistors. The sintering and electrical properties of Mn,Cr-doped ZBS, ZBS(MnCr) varistors werecontrolled using the Sb/Bi ratio. Pyrochlore (Zn2Bi3Sb3O14), α-spinel (Zn7Sb2O12), and δ-Bi2O3 (also β-Bi2O3 at Sb/Bi≤1.0)were detected for all of the systems. Mn and Cr are involved in the development of each phase. Pyrochlore was decomposedand promoted densification at lower temperature on heating in Sb/Bi=1.0 system by Mn rather than Cr doping. A morehomogeneous microstructure was obtained in all systems affected by α-spinel. In ZBS(MnCr), the varistor characteristics wereimproved dramatically (non-linear coefficient, α=40~78), and seemed to form Vo.(0.33eV) as a dominant defect. Fromimpedance and modulus spectroscopy, the grain boundaries can be seen to have divided into two types, i.e. one is tentativelyassigned to ZnO/Bi2O3 (Mn,Cr)/ZnO (0.64~1.1eV) and the other is assigned to the ZnO/ZnO (1.0~1.3eV) homojunction.
Yellow phosphor dispersed color conversion glasses are promising phosphor materials for white LED applications because of their good thermal durability, chemical stability, and anti-ultraviolet property. Six color conversion glasses were prepared with high Tg and low Tg specimens of glass. Luminous efficacy, luminance, CIE (Commission Internationale de l'Eclairage) chromaticity, CCT (Correlated Color Temperature), and CRI (Color Rendering Index) of the color conversion glasses were analyzed according to the PL spectrum. Color conversion glasses with high Tg glass frit, sintered at higher temperature, showed better luminous properties than did color conversion glasses with low Tg glass frit. The characteristics of the color conversion glass depended on the glass composition rather than on the sintering temperature. The XRD peaks of the YAG phosphor disappeared in the color conversion glass with major components of B2O3-ZnO-SiO2-CaO and, in the XRD results, new crystalline peaks of BaSi2O5 appeared in the color conversion glass with major components of Bi2O3-ZnO-B2O3-MgO. The characteristics of CIE chromaticity, CCT, and the CRI of low Tg color conversion glasses showed worse color properties than those of high Tg color conversion glasses. However, these color characteristics of low Tg glasses were improved by thickness variation. So color conversion glasses with good characteristics of both luminous and color properties were attained.
ZnO nanorods were successfully fabricated on Zn foil by chemical bath deposition (CBD) method. The ZnO precursor concentration and immersion time affected the surface morphologies, structure, and electrical properties of the ZnO nanorods. As the precursor concentration increased, the diameter of the ZnO nanorods increased from ca. 50 nm to ca. 150 nm. The thicknesses of the ZnO nanorods were from ca. 1.98μm to ca. 2.08μm. ZnO crystalline phases of (100), (002), and (101) planes of hexagonal wurtzite structure were confirmed by XRD measurement. The fabricated ZnO nanorods showed a photoluminescene property at 380 nm. Especially, the ZnO nanorods deposited for 6 h in solution with a concentration of 0.005M showed a stronger (101) peak than they did (100) or (002) peaks. In addition, these ZnO nanorods showed a good electrical property, with the lowest resistance among the four samples, because the nanorods were densely in contact and relatively without pores. Therefore, a ZnO nanorod substrate is useful as a highly sensitive biochip substrate to detect biomolecules using an electrochemical method.
The electrical properties of a laminated SMD type PTC thermistor for microcircuit protection were investigated as a function of polymer blowing agent addition. Green ceramics for multilayered BaTiO3-based PTCRs were formed by doctor blade method of barium titanate powders; we successfully laminated the sintered ceramic chips to obtain 10 layer chip PTCRs with PTC effect. The sintered density increases with increasing sintering temperature. The electrical properties of the sintered samples were strongly dependent on the calcination and addition of a polymer blowing agent. When BaTiO3 powders containing 0.2 mol% of Y2O3 were calcined at 1000˚C for 2 hrs, the resistivity jump was of 1-2 orders of magnitude. The resistivity at room temperature increases according to the polymer blowing agent addition. Also, the sample using the calcined powder showed a lower resistivity than that of the sample prepared using powders without calcinations. With an increase in the OBSH, the magnitude of the resistivity jumped as a function of the temperature increase. The resistivity of the sintered bodies after the addition of 0.5 wt% polymer blowing agent at 1290˚C for 2 h was shown to be about 8.5Ω·cm; the jump order of the sintered bodies was shown to be on the order of 102.
For the purpose of improving the durability problem, translucent opal glass was fabricated as a substitute for the polycarbonate diffuser of LED lighting. Calcium phosphate was used as an opacifier of opal glass and melted in an electric furnace. The opaque effect was identified according to the change of the cooling procedure. As results, translucent opal glass was obtained by the melting of a batch with a composition of 3.8% calcium phosphate at 1550˚C for 2 hrs and then the cooling of the material in the furnace. For the cooling condition of the glass sample, HTCG (High Temperature Cooled Glass) was found to have better optical properties than LTAG (Low Temperature Annealed Glass). It had excellent optical properties for a diffuser of LED lighting, with no dazzling from direct light due to its high haze value of over 99% and low parallel transmittance value of under 1%. For the thermal properties, it had an expressed thermal expansion coefficient of 5.7×10-6/˚C and a softening point of 876˚C; it also had good thermal properties such as good thermal shock resistance and was easy to apply to the general manufacturing process in the forming of glass tubes and bulbs. Therefore, it is concluded that this translucent opal glass can be used as a glass diffuser material for LED lighting with high heat resistance and high durability; this material is suitable as a substitute for polycarbonate diffusers.
The nutritional properties of the Kochujang were investigated with Fermented Extract of Hizikia fusiforme. No big differences in proximate compositions(moisture, Crude protein, Crude fat, and Crude ash, Carbohyrate) were observed between Two kinds of kochujangs tested in this study, general kochujang purchased from a market(GK), kochujang added with Fermented Extract of Hizikia fusiforme(FGK). However, FGK showed higher level of Total free amino acid(15,929.5 ng/mg), amino nitrogen(1715.88 mg%) and mineral contens than GK. the analysis of volatile compounds using GC/MS revealde than the fermentation dramatically removed off-flavors such as Acetaldehyde, Silane rimethyl(2-methylphenyl)-, 1H-Indole 2-phenyl-1-(trimethylsilyl) in Fermented Extract of Hizikia fusiforme(FGK).
To know proper drying condition for making a safe Sunsik, uncooked food, microbial and physicochemical characteristics of cereal dried by hot-air drying was investigated. As moisture content of 3 Sunsik samples was reduced to about 8%, protein, carbohydrate, fat and ash content of those was increased. But approximate composition of black bean, black rice and glutinous millete and black bean showed little changes during hot-air drying (30, 40, 50oC). Lightness (L value), redness (a value) and yellowness (b value) was increased after hot-air drying. In case of black rice and glutinous millet, b value and L value wasn't changed individually. When we measured a texture for 3 kinds of raw cereal for, hardness of dried cereals was lower than raw cereals. Hardness of dried cereals was increasd as drying temperature was increased. As results of mocrobiologicl experiment for 3 kinds of sunsik on hot-air drying conditions, total cell count was reduced 2 log - 3 log and other pathogenic microorganism wasn't detected except B. cereus.
Cellular microenvironment is an essential issue for regulating epithelial characteristics through the alteration of intricate signaling pathways and intercellular communications in different cell types. Thus, microenvironment influences tumor initiation, progression, and metastasis. This study aimed to investigate the relationship between microenvironment and epithelial property in HPV16 E6/E7-immortalized human oral keratinocytes (IHOKs). To investigate characteristics of IHOK cultured in different media, two media were used, which included keratinocyte growth media (KGM), F-medium composed of 3:1 ratio of DMEM and F-12 (P media) supplemented with 10% FBS and 1% penicillin/streptomycin. Proliferative property and invasive and migratory activity were observed. As results, proliferating activities of IHOK in different culture condition were changed. Likewise, migratory and invasive activities were also different depending on media types. These results suggest that cellular microenvironment can affect modification of biological properties of epithelial cells.
It seems most important for a manufacturing company to be well aware of its relationship with suppliers. This is why it is essential to analyze and control the structural relationship among CEO's characteristics, relations between suppliers and manufacturers and new product development performances affected by such relations. The present study may be summed up as follows: First, from the analysis of characteristics of manufacturing company's CEO and relations between suppliers and manufacturers, it could be verified that CEO's characteristics exercised influence upon sharing of product development process and upon cooperation for technical manpower, but not upon sharing of core technologies, signifying the fact that nothing could be more important than the role of CEO who has strong will to improve his or her relations with suppliers; and Second, from the analysis of relations between suppliers and manufacturers as well as relations between management and new product development performances, it became evident that both management performance and product development performance were affected by sharing of product development process. It was also known that cooperation for technical development process had influence upon the product development performance but not upon the management performance. Furthermore, the analysis showed that both management performance as well as product development performance were affected by sharing of core technologies.